<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title></title>
	<style type="text/css">
		*{
			padding: 0;
			margin: 0;
		}
		.father{
			width: 300px;
			height: 300px;
			margin: 100px;
			border: 10px solid red;
			position: relative;
			padding: 100px;
		}
		.father p{
			width: 100px;
			height: 100px;
			background-color: yellow;
            /*因为脱标了？*/
			position: absolute;
			top: 10px;
			left: 40px;
		}
	</style>
</head>
<body>
	<div class="father">
		<p></p>
	</div>
	
</body>
</html>